The use of biodegradable polymers has been described to reduce the amount of waste materials land-filled and the number of disposal sites. Biodegradable materials have adequate properties to permit them to break down when exposed to conditions which lead to composting. Examples of materials thought to be biodegradable include aliphatic polyesters such as poly (lactic acid), poly(glycolic acid), poly(caprolactone), copolymers of lactide and glycolide, poly(ethylene succinate), and combinations thereof.
Degradation of aliphatic polyesters can occur through multiple mechanisms including hydrolysis, transesterification, chain scission, and the like. Instability of such polymers during processing can occur at elevated temperatures as described in WO 94/07941 (Gruber et. al.).
The processing of aliphatic polyesters as microfibers has been described in U.S. Pat. No. 6,645,618. U.S. Pat. No. 6,111,160 (Gruber et.al.) discloses the use of melt stable polylactides to form nonwoven articles via melt blown and spunbound processes.
Antimicrobial agents (e.g. antibiotics, antiseptics including antiviral, antifungal and antibacterial agents) play an important part in current medical therapy. This is particularly important in the fields of dermatology as well as skin and wound antisepsis. U.S. Patent Application Publication 2005/0089539 (Scholz et.al.) is herein incorporated by reference.
Antimicrobial polymer compositions are known, as exemplified by U.S. Pat. Nos. 5,639,466 (Ford et. al.) and U.S. Pat. No. 6,756,428 (Denesuk). The addition of antimicrobial agents to hydrophilic polypropylene fibers having antimicrobial activity has been described in U.S. Patent Application Publication No. 2004/0241216 (Klun et.al.). These fibrous materials include nonwovens, wovens, knit webs, and knit batts.
The synergistic effect of antimicrobial agents, such as fatty acid monoesters, and enhancers have been described in WO 00/71183 (Andrews et. al.), incorporated herein by reference.